def evalf_log(expr, prec, options):
arg = expr.args[0]
workprec = prec + 10
xre, xim, xacc, _ = evalf(arg, workprec, options)
if xim:
# XXX: use get_abs etc instead
re = evalf_log(C.log(C.Abs(arg, evaluate=False), evaluate=False), prec, options)
im = mpf_atan2(xim, xre or fzero, prec)
return re[0], im, re[2], prec
imaginary_term = mpf_cmp(xre, fzero) < 0
re = mpf_log(mpf_abs(xre), prec, rnd)
size = fastlog(re)
if prec - size > workprec:
# We actually need to compute 1+x accurately, not x
arg = C.Add(S.NegativeOne, arg, evaluate=False)
xre, xim, _, _ = evalf_add(arg, prec, options)
prec2 = workprec - fastlog(xre)
re = mpf_log(mpf_add(xre, fone, prec2), prec, rnd)
re_acc = prec
if imaginary_term:
return re, mpf_pi(prec), re_acc, prec
else:
return re, None, re_acc, None
def evalf_log(expr, prec, options):
arg = expr.args[0]
workprec = prec + 10
xre, xim, xacc, _ = evalf(arg, workprec, options)
if xim:
# XXX: use get_abs etc instead
re = evalf_log(
C.log(C.Abs(arg, evaluate=False), evaluate=False), prec, options)
im = mpf_atan2(xim, xre or fzero, prec)
return re[0], im, re[2], prec
imaginary_term = (mpf_cmp(xre, fzero) < 0)
re = mpf_log(mpf_abs(xre), prec, rnd)
size = fastlog(re)
if prec - size > workprec:
# We actually need to compute 1+x accurately, not x
arg = C.Add(S.NegativeOne, arg, evaluate=False)
xre, xim, _, _ = evalf_add(arg, prec, options)
prec2 = workprec - fastlog(xre)
# xre is now x - 1 so we add 1 back here to calculate x
re = mpf_log(mpf_abs(mpf_add(xre, fone, prec2)), prec, rnd)
re_acc = prec
if imaginary_term:
return re, mpf_pi(prec), re_acc, prec
else:
return re, None, re_acc, None
def calc_part(expr, nexpr):
nint = int(to_int(nexpr, round_nearest))
expr = C.Add(expr, -nint, evaluate=False)
x, _, x_acc, _ = evalf(expr, 10, options)
check_target(expr, (x, None, x_acc, None), 3)
nint += int(no*(mpf_cmp(x or fzero, fzero) == no))
nint = from_int(nint)
return nint, fastlog(nint) + 10
def calc_part(expr, nexpr):
nint = int(to_int(nexpr, round_nearest))
expr = C.Add(expr, -nint, evaluate=False)
x, _, x_acc, _ = evalf(expr, 10, options)
check_target(expr, (x, None, x_acc, None), 3)
nint += int(no * (mpf_cmp(x or fzero, fzero) == no))
nint = from_int(nint)
return nint, fastlog(nint) + 10
def calc_part(expr, nexpr):
nint = int(to_int(nexpr, rnd))
expr = C.Add(expr, -nint, evaluate=False)
x, _, x_acc, _ = evalf(expr, 10, options)
try:
check_target(expr, (x, None, x_acc, None), 3)
except PrecisionExhausted:
if not expr.equals(0):
raise PrecisionExhausted
x = fzero
nint += int(no * (mpf_cmp(x or fzero, fzero) == no))
nint = from_int(nint)
return nint, fastlog(nint) + 10
def calc_part(expr, nexpr):
nint = int(to_int(nexpr, rnd))
expr = C.Add(expr, -nint, evaluate=False)
x, _, x_acc, _ = evalf(expr, 10, options)
try:
check_target(expr, (x, None, x_acc, None), 3)
except PrecisionExhausted:
if not expr.equals(0):
raise PrecisionExhausted
x = fzero
nint += int(no*(mpf_cmp(x or fzero, fzero) == no))
nint = from_int(nint)
return nint, fastlog(nint) + 10